Revert of Expand WTF::StringView's API to be more like StringPiece.

third_party/WebKit/Source/platform/inspector_protocol/String16WTF.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef String16WTF_h
 #define String16WTF_h
 
 #include "platform/Decimal.h"
 #include "public/platform/WebString.h"
 #include "wtf/text/StringBuilder.h"
@@ skipping 55 matching lines @@
     bool endsWith(const String16& s) const { return m_impl.endsWith(s); }
     bool endsWith(UChar character) const { return m_impl.endsWith(character); }
 
 private:
     WTF::String m_impl;
 };
 
 class String16Builder {
 public:
     String16Builder() { }
-    void append(const String16& str) { m_impl.append(StringView(str)); };
+    void append(const String16& str) { m_impl.append(str); };
     void append(UChar c) { m_impl.append(c); };
     void append(LChar c) { m_impl.append(c); };
     void append(char c) { m_impl.append(c); };
     void append(const UChar* c, size_t size) { m_impl.append(c, size); };
     void append(const char* characters, unsigned length) { m_impl.append(characters, length); }
     void appendNumber(int number) { m_impl.appendNumber(number); }
     String16 toString() { return m_impl.toString(); }
     void reserveCapacity(unsigned newCapacity) { m_impl.reserveCapacity(newCapacity); }
 
 private:
@@ skipping 43 matching lines @@
 
 template<>
 struct HashTraits<String16> : SimpleClassHashTraits<String16> {
     static const bool hasIsEmptyValueFunction = true;
     static bool isEmptyValue(const String16& a) { return a.impl().isNull(); }
 };
 
 } // namespace WTF
 
 #endif // !defined(String16WTF_h)